Footwear item comprising built-in dynamic element

ABSTRACT

The invention relates to a shoe or footwear item comprising a sole consisted of an outer face which is intended to come into contact with the ground and an inner face which is intended to come into contact with the foot of the user. According to the invention, the sole includes a dynamic support element which comprises at least two elastically-deformable elements and which is used to store and release energy when said sole is subjected to later stresses. The dynamic support element is positioned in the sole such that it expands at least partially beneath the area corresponding to the front part of the foot. In this way, a dynamic interaction is produced between the two elastically-deformable elements when the sole is subjected to stresses and two corresponding lateral ground support points are obtained, which are located on either side of the longitudinal axis of the shoe.

The present invention relates to the technical field of shoes, and moreparticularly to items of footwear for all kinds of sport.

Such shoes are subjected to considerable mechanical stresses, inparticular when playing sports in which the transfers of weight on theside spring elements are frequent, such as tennis, golf, basketball,football and the like.

The present invention relates more particularly to a sole for suchshoes, since this is the part which takes extreme stresses and strains,while ensuring optimum comfort for the wearers of this footwear.

It is known practice to make shoe soles, for example for sports shoeshaving a sole whose outer face is intended to come into contact with theground and whose inner face is intended to come into contact with thefoot of a wearer.

Shoes having such a sole which also houses a dynamic, elasticallydeformable element are also known.

Document EP 0 516 874 describes a shoe in which the front part of thesole is provided with an insert, of the Belleville washer type, forstoring and releasing energy when walking.

Such a sole is in no way suitable for the above sports, in which thelateral stresses to which the sole and the shoe are subjected are muchmore intense and distributed differently than in a conventional walkingshoe, such as that described in that document.

The aim of the present invention is to produce a sole for a shoeintended for extreme use, in which the side supports of said sole arehighly stressed, so as to encourage the sole and the foot to return to asubstantially normal or antagonist position by reducing energy losses inlateral weight transfers of the front part of the foot.

According to the invention, the above type of footwear item isessentially characterized in that the sole comprises a dynamic supportelement which comprises at least two elastically deformable componentsor parts, for storing and releasing energy when said sole is subjectedto lateral stresses, said dynamic support element being positioned inthe sole such that it lies at least partially beneath a zonecorresponding to the front part of the foot, so as to produce a dynamicinteraction between the two elastically deformable components or partswhen said sole is subjected to stresses and to create two respectivecorresponding lateral points of bearing on the ground, which are locatedon either side of the longitudinal axis of the shoe.

Preferably, the dynamic support element comprises a spring plate,positioned in the sole such as to lie at least partially beneath a zonecorresponding to the arch of the foot, and at least partially beneath azone corresponding to the front part of the foot, so as to produce adynamic interaction between the two parts of the sole thus defined.

Advantageously, the two support components or parts are joined orarranged on the spring plate.

More preferably still, the dynamic support element comprises at leastone set of two support components or parts, arranged longitudinally oneither side of the metatarsus support zone.

According to one embodiment of the sole according to the invention, thespring plate comprises at least four arms, defining an X shape forexample, each of the arms bearing on a pad.

As a variant, the four arms are joined together.

In yet another variant, the four arms are joined together in pairs toconstitute two independent pairs.

Preferably, the pads are located on and in the region of the peripheryof an inner face of an outer layer of the sole, so as to define fourzones of bearing on the ground, on the inner face.

According to one embodiment, each pad is an attached compressible piece.

According to one embodiment, the plate has a central part extendinglongitudinally with respect to a longitudinal axis (L) of the sole, thearms extending obliquely toward the pads from said central part.

According to one embodiment, the central part has a transverse groove,located in said sole in the zone corresponding to the position of themetatarsus, thus allowing elastic deformation of the plate along an axissubstantially normal to the longitudinal axis.

According to one embodiment, the plate has thicker parts, at leastlocally.

The thicker parts are for example made of an elastic material and arelocally thinned.

According to one embodiment, the lateral supports constitute antagonistpaired supports.

According to one embodiment, the dynamic element is a spring plate withshape memory.

According to one embodiment, the plate is fastened by adhesive bondingto the inner face of the outer layer.

According to one embodiment, the spring plate is situated between theouter layer and an intermediate layer, which are separated at leastlocally.

The arms of the spring plate are for example made as a single piece.

Preferably, the spring plate comprises at least one V-shaped piece.

As a variant, the spring plate comprises at least two V-shaped piecesassembled in opposition.

The present invention also aims to provide a shoe or footwear itemcomprising a sole extending in a longitudinal direction, from a frontend to a rear end, whose outer face is designed to come into contactwith the ground and whose inner face is designed to support the footdirectly, characterized in that said sole comprises an element for thedynamic support of the lateral movement of the foot in any directiontransverse to the longitudinal direction, said element being arranged atleast in the front part of the foot and extending in a directionperpendicular to the plane of the sole, or its thickness, between theouter face (including the latter) and the inner face (including thelatter) of said sole, said element comprising at least two supportcomponents or parts for the front part of the foot, arranged in thefront part of the sole respectively on either side of the longitudinaldirection, and aligned in a transverse direction, each support componentbeing elastically deformable in a direction perpendicular to the planeof the sole, short of (compression) and beyond (expansion) a nominalposition or conformation under the effect of the weight of the body, viathe foot, respectively when the foot bears laterally on either of thesupport components and when said bearing force ceases.

Advantageously, the support components or parts are independent of oneanother.

As a variant, the support components or parts are mechanically integral.

Preferably, the structure of the sole is a multi-component structure.

In yet another variant, the structure of the sole is a one-piecestructure.

One advantage of the shoe according to the invention lies in mechanicalsupport for the reactivity of the front of the foot.

The shoe according to the present invention thus allows lateral dynamicsupport for the reactivity of the front of the foot, by encouragingeasier and faster springing back during the bearing phases.Specifically, the dynamic element makes it possible to cause, at thefront of the foot, the parts for bearing on the ground which are inopposition to react. On either side of the metatarsus support zone, thesupport parts are thus one compressed, the other relaxed.

The dynamic element advantageously allows better control of the loads ofthe front of the foot during lateral weight transfers. The wearer feelshis weight distribution better such that he has better control over it.

Moreover, the present invention makes it possible to achieve greaterspeed in lateral weight transfers, the support being amplified.

The shoe sole according to the present invention also provides greaterhorizontal stability for the front of the foot, by improving footsuspension.

Further features and advantages will also become clear from thefollowing detailed description, with reference to the drawings attachedby way of illustrative example, in which:

FIG. 1 is a perspective view of a shoe or footwear item for racketsports, having a sole according to the present invention;

FIG. 2 is an exploded view of an embodiment of a sole according to theinvention;

FIG. 3 is a view from beneath of the sole of FIG. 2;

FIG. 4 is a section along the line IV-IV in FIG. 3;

FIG. 5 is a section along the line V-V in FIG. 3;

FIGS. 6 and 7 are schematic depictions of an example of how a dynamicelement of a sole according to the invention works;

FIGS. 8 to 11 are, respectively, perspective and transverse sectionalviews of the dynamic element in two variants according to the presentinvention.

The shoe 10 or footwear item according to the present invention shown inperspective in FIG. 1 is a shoe more particularly designed to be wornwhen playing sports such as tennis, squash, golf, or alternativelybadminton. Naturally, the shoe 10 according to the present invention maybe worn for other sports without restriction.

When playing such sports, a person often has to swing his body inlateral movements left to right and vice versa. There are a great manylateral to-and-fro movements throughout the game, and they must berapid.

The shoe 10 has a built-in sole as shown in FIG. 2 which comprises forexample an outer layer 1. The latter has an outer face 1 a intended tocome into contact with the ground and an inner face 1 b. The outer face1 a may be covered with various coverings likely to improve its grip onthe ground. The sole extends between a front end 20 and a rear end 30,in a longitudinal direction L.

The sole of FIG. 1 also comprises an intermediate layer 2 intended to beplaced on top of the outer layer 1, and on which is placed an additionalsole called an inlay sole (not shown). This intermediate layer has aninner face 2 b intended to come into contact with the wearer's foot. Theouter layer 1 may also be provided locally with upright edges 1 c, 1 d,between which the intermediate layer 2 is placed.

According to an essential feature of the present invention, the dynamicelement takes the form of a spring plate 3 placed in the sole, at alevel which depends on the internal structure of the sole. The functionof this plate is independent of the number of strata of which the soleis composed, it only matters that the wearer can bear on this plate whenplaying, in particular during lateral spring movements.

Between the outer layer 1 and the intermediate layer 2 is placed, forexample, the spring plate 3 forming a dynamic support element of thesole. Such a dynamic element makes it possible to store and releaseenergy generated by considerable mechanical stresses and strains of theshoe and hence of the sole, i.e. as the foot moves laterally in atransverse direction T which is substantially perpendicular to thelongitudinal direction L.

The spring plate 3 is for example fastened by adhesive bonding to theinner face 1 b.

The intermediate layer 2 is attached to the outer layer 1, moreparticularly fastened to the inner face 1 a of the latter, so as tocreate the sole according to the invention.

The outer layer 1 and the intermediate layer 2 are separated at leastlocally, particularly in the region of the spring plate 3. Theintermediate layer 2 is fastened to the outer layer 1 at a part 1 eforming the heel of the sole and at the periphery or upright edges 1 c,1 d of a front part 1 f.

The spring plate 3, shown in particular in FIGS. 2 and 3, comprises fourarms 4, 5, 6 and 7 joined together and defining for example an X shape.

Each of the arms 4, 5, 6 and 7 bears on a corresponding pad 4 a, 5 a, 6a and 7 a, located on and in the region of the periphery of the innerface 1 b.

The pads 4 a, 5 a, 6 a and 7 a thus define four lateral zones of bearingon the ground, on the inner face 1 b.

Each pad 4 a, 5 a, 6 a and 7 a consists for example of a compressiblepiece attached to the inner face 1 b (cf. FIGS. 5 and 6).

As a variant, each of the pads may be made by a slight deformation,thicker part or clearance of material on the inner face 1 b, serving toposition the ends of the respective arms 4, 5, 6 and 7.

Moreover, the pads 4 a to 7 a may, as a variant, be located notunderneath the arms but situated above the arms of the plate.

The spring plate 3 preferably has a central part 8 extendinglongitudinally with respect to a longitudinal axis L of the sole.

The arms 4, 5, 6 and 7 extend obliquely from said central part 8 towardthe corresponding pads 4 a, 5 a, 6 a and 7 a.

According to the invention, the arms 4 to 7 extend on either side of thelongitudinal axis defined by the metatarsus support zone so that thepads are situated on either side of this axis. Two pairs of pads arethus defined, one consisting of the pads 4 a and 5 a, and the other ofthe pads 6 a and 7 a. Within each of these pairs, the pads interact inopposition to allow the foot to spring back laterally.

Thus, when the pad 4 a is compressed, the opposite pad 5 a is relaxed,and vice versa. The same goes for the pair of pads 6 a and 7 a.

The pads may also be considered as support zones or components. They maybe either independent of one another or mechanically integral.

The central part 8 also has a transverse groove 9, extending in thesole, following a zone corresponding to the position of the metatarsus,when the spring plate 3 is fastened to the inner face 1 b.

This groove 9 thus allows the spring plate 3 to deform elastically,along an axis substantially normal to the longitudinal axis L andcoinciding with said groove 9.

In one embodiment, the spring plate 3 also has thicker parts 3 a.

One embodiment of these thicker parts 3 a is shown for example in FIGS.2, 3 and 4.

The thicker parts 3 a are made of a material whose elasticity allows adeformation when one or more of the arms 4 to 7 is compressed andpromotes the return to the initial position. The thicker parts are forexample thinner at the center or alternatively arched to enhance thecompression/expansion function of the spring plate.

This compression/expansion function can moreover be enhanced bymultiplying the lateral bearing points, by for example increasing thenumber of arms of the spring plate. This makes it possible to obtain anincreasingly local reaction to stresses, and even a degree ofgradualness in this reaction. This function may also be achieved bycreating recesses in the spring plate.

The outer layer 1 is for example provided with openings 10 and 11, inwhich the thicker parts 3 a are engaged and positioned.

The openings 10 and 11 may advantageously be covered or filled with atransparent material, making it possible to see, through the outer layer1, at least part of the spring plate 3.

Likewise, the outer layer 1 may also have complementary transparentzones, facing the pads 4 a, 5 a, 6 a and 7 a or the ends of the arms 4,5, 6, 7, so as to make the zones corresponding to the lateral supportsvisible through the outer face 1 a.

The spring plate 3 is for example metal or made of a high-performanceplastic, or alternatively of a composite.

The intermediate layer 2, and the outer layer 1, are made for example ofrubber.

The sole may for example have a one-piece structure such that thedynamic support element is embedded in one of the layers or strata ofthe sole, or in the single layer.

According to a variant that has not been shown, the intermediate layer 2may have slits facing the arms 4, 5, 6, 7 in which are placed insertsmade of highly deformable and elastic materials (for example elastomer,polyurethane, etc.).

With their elastic properties, these inserts make it possible to improvethe springing back of the front of the foot.

The inserts with a shape complementary to the slits preferably haveshapes identical or similar to the shapes of the arms 4, 5, 6 and 7.

In yet another variant that has not been shown, the sole may be reducedto a single stratum, and consist for example only of the outer layer 1,the spring plate and the pads being embedded in the latter.

FIGS. 6 and 7 show how the spring plate 3 works.

At rest, i.e. when the sole is not stressed, the spring plate 3 liessubstantially flat as shown schematically in FIG. 6.

When the wearer bears laterally at the front with the front part of hisfoot, shown for example in FIG. 7, the arm 7 is deformed elasticallyalong the arrow D and compresses the pad 7 a.

At the same time, the arm 5 deforms elastically and antagonisticallyalong the arrow R and expands the pad 5 a. Likewise, the pad 6 aopposite the pad 7 a is relaxed. Likewise, the pad 4 a may becompressed. The wearer may thus not only cause the dynamic element to besubjected to lateral stresses but also stresses along the diagonal ofthis element.

The sole thus accompanies the movement of the foot, in particular whenthe foot bears laterally on the sole. Moreover, the energy stored byvirtue of the stressing of the spring plate 3 helps the foot return toanother position or a rest position once the abovementioned lateralbearing forces cease.

Each lateral bearing force exerted by the foot may thus be passed on toone of the arms 4, 5, 6, 7 and may thus be supported via the functioningof the spring plate 3.

The arms 4 to 7 of the spring plate 3 are for example made as one piece.As a variant, the spring plate is obtained by fastening together twoV-shaped pieces assembled in opposition.

The dynamic support element may be made using any kind of material withelastic properties and take any geometric shape suitable for the sportplayed with the shoe. The structure of this element must make itpossible to create at least two antagonistic lateral supports located oneither side of the longitudinal axis L of the shoe, situated in thefront part of the sole.

Thus, in another variant as shown in FIGS. 8 and 9, the dynamic supportelement 40 has constituent parts situated in the direction of thethickness of the sole. It thus has two V-shaped pieces 41, 42 whoserespective arms 43, 44 and 45, 46 are situated one on top of the other.Inside each pair of arms are elastic pads 47 and 48 (FIG. 9); as avariant, as shown in FIG. 8, the pads may be dispensed with and bereplaced by air. The two pairs are mounted back to back, being joined atthe base of the V.

In yet another variant shown in FIGS. 10 and 11, the dynamic element 50also consists of two pairs 51, 52 of arms which are spaced apart fromone another and are in the shape of a V with their respective bases 53,54 extending over a certain width. The pads 47 and 48 are situated alongthe longitudinal edges of the shoe, in the front part of the sole.

The shoe sole according to the present invention thus makes it possibleto facilitate lateral springing back by reducing energy losses inlateral weight transfers of the front of the foot. The wearer has bettercontrol over the stress forces of the front of the foot since he canfeel his weight distribution better. Moreover, the horizontal stabilityof the front of the foot is improved thanks to better suspension. Thedynamic element also ensures greater speed in lateral weight transfersby increasing the springing effect.

It goes without saying that the invention is not limited only to theembodiments described above by way of example. On the contrary, itencompasses all variants. Thus, in particular, the features presentedabove could be combined differently without thereby departing from thescope of the invention.

1. A footwear item comprising: a sole component extending in alongitudinal direction from a front end of the footwear item to a rearend of the footwear item, wherein an outer face of the sole component isdesigned to come into contact with the ground and wherein an inner faceof the sole component is designed to support a foot of a wearerdirectly, the sole component comprising a dynamically responsiveintegral insert in a front part of the sole component, extending in atransverse direction across a longitudinal direction and extendingbetween the outer face and the inner face of the sole component in aplane perpendicular to the sole component, the dynamically responsiveintegral insert comprising two resilient weight supporting elementsrespectively disposed on two sides of the longitudinal direction, theresilient weight supporting elements antagonistically acting around thelongitudinal direction, each resilient weight supporting element beingpivotally arranged around the longitudinal direction to be angularlyelastically charged around the longitudinal direction against any localand lateral dynamic loading of a metatarsus part of the foot on eitherside of the longitudinal direction, caused by a transverse transfer ofweight of the wearer from one side to an other side of the footwearitem.
 2. A footwear item comprising: a sole component extending in alongitudinal direction from a front end of the footwear item to a rearend of the footwear item, wherein an outer face of the sole component isdesigned to come into contact with the ground and wherein an inner faceof the sole component is designed to support a foot of a wearerdirectly, the sole component comprising a dynamically responsiveintegral insert in a front part of the sole component; wherein thedynamically responsive integral insert is designed for a lateralmovement of the foot in any direction transverse to the longitudinaldirection, and extending in a transverse direction across thelongitudinal direction and extending between the outer face and theinner face of the sole component in a plane perpendicular to a plane ofthe sole component, and wherein the dynamically responsive integralinsert comprises: at least two resilient weight supporting elementslocated in a front part of the dynamically responsive integral insertand on opposite sides of an axis extending in the longitudinaldirection, and aligned in a transverse direction, each resilient weightsupporting element being elastically deformable in a directionperpendicular to the plane of the sole component, and wherein theresilient weight supporting elements antagonistically act around thelongitudinal direction, and each resilient weight supporting elementbeing pivotally arranged around the longitudinal direction to beangularly elastically charged around the longitudinal direction againstany local and lateral dynamic loading of a metatarsus part of the footon either side of the longitudinal direction, caused by a transversetransfer of weight of the wearer from one side to an other side of thefootwear item.
 3. The footwear item as claimed in claim 1, wherein thedynamically responsive integral insert further comprises a spring plateand is positioned in the sole such as to lie at least partially beneatha zone corresponding to an arch of the foot, and at least a part of thefront part of the foot.
 4. The footwear item as claimed in claim 3,wherein the resilient weight supporting elements are joined on thespring plate.
 5. The footwear item as claimed in claim 4, wherein thespring plate comprises at least four arms, defining an X shape, each ofthe arms bearing on a pad constituting an elastically deformablecomponent.
 6. The footwear item as claimed in claim 5, wherein each padis an attached compressible piece.
 7. The footwear item as claimed inclaim 5, wherein the spring plate has a central part extendingtransversely with respect to a longitudinal axis of the sole component,the arms extending obliquely toward the pads from said central part. 8.The footwear item as claimed in claim 7, wherein the central part has atransverse groove, located in said sole component in a zonecorresponding to a position of the metatarsus part of the foot, allowingelastic deformation of the spring plate along an axis substantiallynormal to the longitudinal axis.
 9. The footwear item as claimed inclaim 5, wherein the spring plate has thicker parts, at least locally.10. The footwear item as claimed in claim 9, wherein the thicker partsare made of an elastic material and are locally thinned.
 11. Thefootwear item as claimed in claim 5, wherein the dynamically responsiveintegral insert is a spring plate with shape memory.
 12. The footwearitem as claimed in claim 5, wherein the spring plate is fastened byadhesive bonding to the inner face of an outer layer of the solecomponent.
 13. The footwear item as claimed in claim 5, wherein thespring plate comprises at least one V-shaped piece.
 14. The footwearitem as claimed in claim 5, wherein the spring plate comprises at leasttwo V-shaped pieces assembled in opposition.
 15. The footwear item asclaimed in claim 2, wherein the resilient weight supporting elements areindependent of one another.
 16. The footwear item as claimed in claim 2,wherein the resilient weight supporting elements are mechanicallyintegral.
 17. The footwear item as claimed in claim 2, wherein astructure of the sole component is a multi-component structure.
 18. Thefootwear item as claimed in claim 2, wherein a structure of the solecomponent is a one-piece structure.